Design and properties of the Spitfire Mk. 21+ wing

[spicmart]

The Spitfire Mk. 21 introduced a new wing which much improved the fighter's handling and agility at high speeds. Potential aileron reversal would occur at over 1300 km/h.

This would erase the Spitfire's one weakness in a dogfight.

Does that make it the best dogfighting/interceptor plane together with the F8F Bearcat?

Both machines clocked at a top speed of about 740 km/h which made them around 40 to 50 km/h slower than the fastest props such as the Spiteful or P-51H (and perhaps the projected Fw 190D with Jumo 213 EB).

How stiff were the wings of other late-war fighters?

Which of these superprops would you prefer?

Any more details about the Spit 21 wing?

 

[Shortround6]

Be very careful about top speed with/without racks and what boost is used.

 

[wuzak]

Does that make it the best dogfighting/interceptor plane together with the F8F Bearcat?

Both machines clocked at a top speed of about 740 km/h which made them around 40 to 50 km/h slower than the fastest props such as the Spiteful or P-51H (and perhaps the projected Fw 190D with Jumo 213 EB).

That performance is for the F8F-2, which started production in 1948.

The F8F-1, just being delivered at the end of the war, was 60-70km/h slower.

The Spitfire 21 was in service in early 1945. The Spitfire 24 was in production from 1946 and in service in 1948.

The Spitfire XIV could still turn inside the Spitfire 21, but the Spitfire 21 had a much greater rate of roll, and could carry much heavier ordnance.

 

[GregP]

There wasn't a Spitfire that could get to 1300 km/h in any configuration that was still in one piece.

The max safe speed ever reached was 975 km/h by Squadron Leader J. R. Tobin in a Mk XI. That same Mk XI late in 1944 reached 1000 km/h when the propeller failed, but it never was EVER going to get to 1300 km/h with the wings and propeller still attached. Likely not if the wings ripped off due to the fuselage not being able to remain in controlled, straight flight in any direction, including downward.

 

[wuzak]

There wasn't a Spitfire that could get to 1300 km/h in any configuration that was still in one piece.

No-one said it would.

That was the calculated aileron reversal speed for the Mk 21.

Which means that it would never experience that issue in practice, unlike earlier marks of Spitfire.

 

[GregP]

The post reads like it, Wayne, but I take your point.

A Spitfire 21 (and a Spitfire 24) is one of my favorite airplanes.

Cheers.

 

[dedalos]

From the ultimate sinle engine piston engine fighters i like the sea fury and f4U-5. The combined high performance (even if not the absolute top) , stuctural strength and damage resistance
But even above these l like the De Havilland Hornet Mk1

 

[Skewgear]

Difficult to say one way or another without comparative data. Against what do you seek to compare the Mk.XXI and is that a fair comparison given the historical setting and tactical doctrine for employing the aircraft?

A machine designed for speed above other considerations may be a poor dogfighter. Used in connection with its intended concept of operations (e.g. boom and zoom, bomber interceptor, etc) it may well be the best in its field.

You wouldn't compare a Hawker Hart with a Ta152H because the setting doesn't match - they would never have met in reality - the conops for each doesn't match at all and by certain individual measures (sustained turn radius, top speed, max altitude) one has a huge advantage over the other that doesn't mean much in reality.

 

[spicmart]

That performance is for the F8F-2, which started production in 1948.

The F8F-1, just being delivered at the end of the war, was 60-70km/h slower.

The Spitfire 21 was in service in early 1945. The Spitfire 24 was in production from 1946 and in service in 1948.

The Spitfire XIV could still turn inside the Spitfire 21, but the Spitfire 21 had a much greater rate of roll, and could carry much heavier ordnance.

Sure, but which high-performance fighter else could turn with Spitfire. The Bearcat. At least so I heard.

 

[Shortround6]

Sure, but which high-performance fighter else could turn with Spitfire. The Bearcat. At least so I heard.

Climb rates for the two are all over the place, depending on power used and altitude. They are within 0.1-0.2 minutes of each other getting to 20,000ft but at sea level the F8F-1 is 1200fpm faster, but it goes away quickly. At 20,000ft the Spit 21 is climbing just over 500fpm quicker.
At 34,800ft the Spitfire 21 is climbing about 800fpm faster and here that is significant as we are comparing 500fpm to about 1300fpm.

At low altitudes the F8F-1 may very well be superior, the question is at what altitude are they equal or the Spitfire start showing better performance?

 

[PAT303]

Two different aircraft designed for two different purposes, the Spit 21 would have to be an LF version to make them comparable.

 

[MIflyer]

You can download a copy of the Spit 21 pilot's notes here:

Aviation Archives

aviationarchives.blogspot.com

 

[spicmart]

Edit*:

Afaik the 190/152 family had only the advantage of superior roll rate against the Spitfire?

It may have lost even this advantage against the new-wing-Spits 21 and up.

Speed was the only trump card then for the Fw 190D with Jumo 213EB?

 

[spicmart]

What would it take to build a Focke Wulf fighter which was on par with these very late Spits in terms of all-around dogfighting agility?

 

[EwenS]

Only 2 squadrons flew the Spitfire XXI in WW2 -

91squadron swapped its Spitfire IX for the new model in April 1945.
1 squadron followed in May 1945.

 

[tomo pauk]

What would it take to build a Focke Wulf fighter which was on par with these very late Spits in terms of all-around dogfighting agility?

Make a jet fighter.

 

[Shortround6]

What would it take to build a Focke Wulf fighter which was on par with these very late Spits in terms of all-around dogfighting agility?

1. Loud thunderclaps
2. Parting of the clouds
3. Beams of golden light.
4. Choruses of angels.

Basically Devine intervention.

 

[Shortround6]

What would it take to build a Focke Wulf fighter which was on par with these very late Spits in terms of all-around dogfighting agility?

To be less flippant you need a power plant with a similar power to weight ratio. Or you need to figure out how much you can save if you use a heavier power plant.
British had several advantages. Better raw materials for fuel, Better raw materials for steel and engine parts.
Things the Germans (Focke Wulf) can do. Use fewer guns/less ammo to get the power loading and wing loading down.
Accept even shorter engine life for a lighter engine of the needed power to hold the power loading and wing loading down. One account claims that the Jumo 213 was good for about 50 hours as it was was engine life.

Basically the late model FW TA 152s were about 1000-1500lbs heavier than the Spit 21 and used a wing about 10% smaller. Forget the 152H wing, even a shorter span but larger area wing closer in size to the Spit 21 wing is needed. Now you need to get the weight down. A lot.

We can discuss airfoils, fancy lift devices, and other small bits after the power to weight ratio and wing loading get a lot closer together.

 

[tomo pauk]

Forget the 152H wing, even a shorter span but larger area wing closer in size to the Spit 21 wing is needed. Now you need to get the weight down. A lot.

Ain't gonna happen with the historical engines that Fw/Ta fighters used.

Unless there is a jet engine in the play, having an earlier DB 605L with the compression ratio slashed down to at least 6.5:1 (if not lower) can help with weight. Lower CR in order that a greater boost (1.9 - 2 ata, hopefully, instead of 1.75) can be used under 9 km, for greater power. I'm not sure how easy it will be to outfit the 605L with the intercooler, for an even greater boost.
Don't over-do the weaponry, and don't cram obscene amounts of fuel. Keep the wing from Antons and Doras.

Still, since this is 1945 an beyond with Spitfire 21 realistic use, a Fw jet fighter still gets my vote.

 

[spicmart]

Ain't gonna happen with the historical engines that Fw/Ta fighters used.

Unless there is a jet engine in the play, having an earlier DB 605L with the compression ratio slashed down to at least 6.5:1 (if not lower) can help with weight. Lower CR in order that a greater boost (1.9 - 2 ata, hopefully, instead of 1.75) can be used under 9 km, for greater power. I'm not sure how easy it will be to outfit the 605L with the intercooler, for an even greater boost.
Don't over-do the weaponry, and don't cram obscene amounts of fuel. Keep the wing from Antons and Doras.

Still, since this is 1945 an beyond with Spitfire 21 realistic use, a Fw jet fighter still gets my vote.

Staying with piston fighters, what about your 190 lite with laminar flow wing and DB 605L (or 2000 PS versions of that engine)? The Me 109K-14 made 728 km/h with it so the 190 lite might be about as fast as the fastest Spitfire.